package com.hqyj.javaSpringBoot.interceptor;


import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.ui.ModelMap;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 自动封装template路径
 * 约定：目标页面的相对路径地址与path路径保持一致
 */
@Component
public class ViewMappingInterceptor implements HandlerInterceptor {

    private final static Logger LOGGER = LoggerFactory
            .getLogger(ViewMappingInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response,
                             Object handler) throws Exception {
        LOGGER.debug("====ViewMappingInterceptor pre handle====");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
                           HttpServletResponse response,
                           Object handler, ModelAndView modelAndView) throws Exception {
        LOGGER.debug("====ViewMappingInterceptor post handle====");
        //判断请求是否返回view，如果是rest接口||redirect||forward，则不做处理
        if (modelAndView == null ||
                modelAndView.getViewName().startsWith("redirect") ||
                modelAndView.getViewName().startsWith("forward")) {
            return;
        }
        //从请求中得到path
        String path = request.getServletPath();
        //判断modelMap中是否有设置template，如果有，则无需设置
        String template = (String) modelAndView.getModelMap().get("template");
        if (StringUtils.isBlank(template)) {
            //在modelMap中设置template，值为path
            path = path.startsWith("/") ? path.substring(1) : path;
            modelAndView.getModelMap().addAttribute("template", path);
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request,
                                HttpServletResponse response,
                                Object handler, Exception ex) throws Exception {
        LOGGER.debug("====ViewMappingInterceptor after handle====");
    }
}
